Generally, this invention relates to a system for providing heat to a tractor's cabin and engine. In particular, this invention relates to a temperature control system for tractors pulling temperature controlled trailers wherein the cooling system of the temperature controlled trailer is interconnected to the tractor cabin's heating system and the tractor engine's cooling system. Consequently, when the truck occupant is resting, during what is normally idle time for the truck, the tractor's engine can be shut down and the trailer's engine, which is required to continue operating keeping the temperature controlled trailer cool, can be used to provide heat to the tractor's cabin and engine.
Normally, during cold climate, a tractor's engine is kept continuously running at idle when the tractor is parked to provide electrical power and heat to the tractor's cabin when the occupant is sleeping. This process, however, is not economical or environmentally safe. Such practice reduces the life of the engine, requires more frequent oil changes, wastes fuel, and produces noxious exhaust fumes.
Additionally, many tractor trailers pull temperature controlled trailer units commonly known as refer trailers which carry perishable goods. The refer motors are also required to continuously operate to control the temperature in the refer trailer and prevent perishable goods from spoiling. Thus, when the tractor is parked, two engines are in operation at the same time, for controlling the temperature of two separate compartments, the refer trailer and the tractor's cabin.
U.S. Pat. No. 4,825,663 discloses an auxiliary power system that provides heating to a tractor's engine and to a tractor's cabin when the tractor's engine is not running. In addition, the auxiliary engine provides electrical power to the main engine's electrical system. This auxiliary system, however, requires redundant equipment and an additional engine separate from the tractor's engine resulting in the the overall weight of the tractor and trailer to increase. However, because the overall tractor's weight is an element to the cost of operation, the added weight to the trailer is not desirable since the added weight increases the cost of operation of the trailer.
U.S. Pat. No. 4,756,359 discloses an auxiliary system for providing air conditioning and heating for the tractor's cabin, as well as heat for the tractor's engine. This auxiliary system, however, uses a belt system to connect the auxiliary system with the main engine's air conditioning compressor and alternator. The hot exhaust from the auxiliary engine provides the heat to the tractor's cabin and engine via heat exchangers. The additional auxiliary engine in this system also adds to the overall weight of the tractor and consequently is not desirable.
Accordingly, it is an object of the present invention to provide heat to a tractor's cabin in an economical manner when the tractor is parked;
Furthermore, it is an object of the present invention to provide heat to a tractor's cabin when the tractor is parked by utilizing the heat from a refrigerated trailer's engine; PA1 Also, it is an object of the present invention to provide heat to a tractor's cabin by interconnecting the refrigerated motor's coolant system to the cabin heating system; PA1 Furthermore, it is the object of this invention to provide heat to both the tractor's cabin and the tractor's engine while the tractor's engine is shutdown to avoid cold startups which increases the difficulty in starting;